Such an optical subassembly is required, for example, for optical sensors or communication devices, in the case of which a receiver sensitive for electromagnetic radiation and/or a transmitter transmitting electromagnetic radiation are/is accommodated in a housing. For the interaction of the transmitter, or receiver, as the case may be, with the environment outside of the housing, it is necessary to couple electromagnetic radiation into, or out of, the housing. An optical sensor for performing absorption measurements or measurements of attenuated total reflectance, so-called ATR-measurements, can be so embodied, that a radiation source and a spectrometer are accommodated in a housing, while a probe for immersion into a process medium outside of the housing is connected via optical fibers with the radiation source and with the spectrometer. In this case, in the measuring, electromagnetic radiation of the radiation source is coupled out of the housing, brought via the optical fibers into the probe, there reflected, and then coupled via optical fibers back into the housing, where it falls on the detector of the spectrometer. German Gebrauchsmuster DE 295 21 685 U1 discloses an optical component, intended especially for an infrared radiator, having a housing, which has an opening closed by means of an optical window or lens of sapphire for radiation entering, or leaving, the housing, wherein, between the edge of the opening and the window or lens, an encircling, metal solder connection is provided. This optical component seals the housing vacuum-tightly.
German Gebrauchsmuster DE 20 2006 014 464 U1 discloses a sensor arrangement, in the case of which electromagnetic radiation can be coupled into, or out of, a housing, through a housing opening. For this, there is provided in the housing an opening, which is covered with a window transmissive for the electromagnetic radiation. The window is pressed against the housing at its edge, with interpositioning of a seal. This tightly seals the housing, even under demanding conditions, such as a liquid pressure of up to 100 bar and a temperature of up to 50° C.
DE 102 46 762 A1 shows a communication window for a pressure-tight housing having an opening in a housing wall. The opening is embodied as an optically transparent, elongated window pane and is arranged within a sleeve-shaped, screw-threaded frame, which can be pressure-tightly screwed into the opening.